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He X, Zhong D, Zou C, Pi L, Zhao L, Qin Y, Pan M, Wang S, Zeng W, Xiang Z, Chen X, Wu Y, Si Y, Cui L, Huang Y, Yan G, Yang Z. Unraveling the Complexity of Imported Malaria Infections by Amplicon Deep Sequencing. Front Cell Infect Microbiol 2021; 11:725859. [PMID: 34595134 PMCID: PMC8477663 DOI: 10.3389/fcimb.2021.725859] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/15/2021] [Accepted: 08/16/2021] [Indexed: 11/22/2022] Open
Abstract
Imported malaria and recurrent infections are becoming an emerging issue in many malaria non-endemic countries. This study aimed to determine the molecular patterns of the imported malaria infections and recurrence. Blood samples were collected from patients with imported malaria infections during 2016-2018 in Guangxi Zhuang Autonomous Region, China. Next-generation amplicon deep-sequencing approaches were used to assess parasite genetic diversity, multiplexity of infection, relapse, recrudescence, and antimalarial drug resistance. A total of 44 imported malaria cases were examined during the study, of which 35 (79.5%) had recurrent malaria infections within 1 year. The majority (91.4%) had one recurrent malaria episode, whereas two patients had two recurrences and one patient had three recurrences. A total of 19 recurrence patterns (the species responsible for primary and successive clinical episodes) were found in patients returning from malaria epidemic countries. Four parasite species were detected with a higher than usual proportion (46.2%) of non-falciparum infections or mixed-species infections. An increasing trend of recurrence infections and reduced drug treatment efficacy were observed among the cases of imported malaria. The high recurrence rate and complex patterns of imported malaria from Africa to non-endemic countries have the potential to initiate local transmission, thereby undermining efforts to eliminate locally acquired malaria. Our findings highlight the power of amplicon deep-sequencing applications in molecular epidemiological studies of the imported malaria recurrences.
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Affiliation(s)
- Xi He
- Department of Pathogen Biology and Immunology, Kunming Medical University, Kunming, China
| | - Daibin Zhong
- Program in Public Health, College of Health Sciences, University of California at Irvine, Irvine, CA, United States
| | - Chunyan Zou
- Department of Electrocardiogram, Guangxi Zhuang Autonomous Region People’s Hospital, Nanning, China
| | - Liang Pi
- Department of Pathogen Biology and Immunology, Kunming Medical University, Kunming, China
| | - Luyi Zhao
- Department of Pathogen Biology and Immunology, Kunming Medical University, Kunming, China
| | - Yucheng Qin
- Department of Infectious Diseases, Shanglin County People’s Hospital, Shanglin, China
| | - Maohua Pan
- Department of Infectious Diseases, Shanglin County People’s Hospital, Shanglin, China
| | - Siqi Wang
- Department of Pathogen Biology and Immunology, Kunming Medical University, Kunming, China
| | - Weiling Zeng
- Department of Pathogen Biology and Immunology, Kunming Medical University, Kunming, China
| | - Zheng Xiang
- Department of Pathogen Biology and Immunology, Kunming Medical University, Kunming, China
| | - Xi Chen
- Department of Pathogen Biology and Immunology, Kunming Medical University, Kunming, China
| | - Yanrui Wu
- Department of Cell Biology & Genetics, Kunming Medical University, Kunming, China
| | - Yu Si
- Department of Pathogen Biology and Immunology, Kunming Medical University, Kunming, China
| | - Liwang Cui
- Department of Internal Medicine, Morsani College of Medicine, University of South Florida, Tampa, FL, United States
| | - Yaming Huang
- Department of Protozoa, Guangxi Zhuang Autonomous Region Center for Disease Prevention and Control, Nanning, China
| | - Guiyun Yan
- Program in Public Health, College of Health Sciences, University of California at Irvine, Irvine, CA, United States
| | - Zhaoqing Yang
- Department of Pathogen Biology and Immunology, Kunming Medical University, Kunming, China
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Kim A, Popovici J, Menard D, Serre D. Plasmodium vivax transcriptomes reveal stage-specific chloroquine response and differential regulation of male and female gametocytes. Nat Commun 2019; 10:371. [PMID: 30670687 PMCID: PMC6342968 DOI: 10.1038/s41467-019-08312-z] [Citation(s) in RCA: 25] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/26/2018] [Accepted: 12/26/2018] [Indexed: 12/12/2022] Open
Abstract
Studies of Plasmodium vivax gene expression are complicated by the lack of in vitro culture system and the difficulties associated with studying clinical infections that often contain multiple clones and a mixture of parasite stages. Here, we characterize the transcriptomes of P. vivax parasites from 26 malaria patients. We show that most parasite mRNAs derive from trophozoites and that the asynchronicity of P. vivax infections is therefore unlikely to confound gene expression studies. Analyses of gametocyte genes reveal two distinct clusters of co-regulated genes, suggesting that male and female gametocytes are independently regulated. Finally, we analyze gene expression changes induced by chloroquine and show that this antimalarial drug efficiently eliminates most P. vivax parasite stages but, in contrast to P. falciparum, does not affect trophozoites.
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Affiliation(s)
- Adam Kim
- Institute for Genome Sciences, University of Maryland School of Medicine, 670 W Baltimore Street, Baltimore, MD, 21201, USA
| | - Jean Popovici
- Malaria Molecular Epidemiology Unit, Institut Pasteur in Cambodia, 5 Boulevard Monivong, PO Box 983, Phnom Penh, 12 201, Cambodia
| | - Didier Menard
- Malaria Molecular Epidemiology Unit, Institut Pasteur in Cambodia, 5 Boulevard Monivong, PO Box 983, Phnom Penh, 12 201, Cambodia
- Biology of Host-Parasite Interactions Unit, Institut Pasteur, 25-28 Rue du Dr. Roux, 75724, Paris, France
| | - David Serre
- Institute for Genome Sciences, University of Maryland School of Medicine, 670 W Baltimore Street, Baltimore, MD, 21201, USA.
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Zhong D, Lo E, Wang X, Yewhalaw D, Zhou G, Atieli HE, Githeko A, Hemming-Schroeder E, Lee MC, Afrane Y, Yan G. Multiplicity and molecular epidemiology of Plasmodium vivax and Plasmodium falciparum infections in East Africa. Malar J 2018; 17:185. [PMID: 29720181 PMCID: PMC5932820 DOI: 10.1186/s12936-018-2337-y] [Citation(s) in RCA: 28] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/13/2017] [Accepted: 04/26/2018] [Indexed: 11/18/2022] Open
Abstract
Background Parasite genetic diversity and multiplicity of infection (MOI) affect clinical outcomes, response to drug treatment and naturally-acquired or vaccine-induced immunity. Traditional methods often underestimate the frequency and diversity of multiclonal infections due to technical sensitivity and specificity. Next-generation sequencing techniques provide a novel opportunity to study complexity of parasite populations and molecular epidemiology. Methods Symptomatic and asymptomatic Plasmodium vivax samples were collected from health centres/hospitals and schools, respectively, from 2011 to 2015 in Ethiopia. Similarly, both symptomatic and asymptomatic Plasmodium falciparum samples were collected, respectively, from hospitals and schools in 2005 and 2015 in Kenya. Finger-pricked blood samples were collected and dried on filter paper. Long amplicon (> 400 bp) deep sequencing of merozoite surface protein 1 (msp1) gene was conducted to determine multiplicity and molecular epidemiology of P. vivax and P. falciparum infections. The results were compared with those based on short amplicon (117 bp) deep sequencing. Results A total of 139 P. vivax and 222 P. falciparum samples were pyro-sequenced for pvmsp1 and pfmsp1, yielding a total of 21 P. vivax and 99 P. falciparum predominant haplotypes. The average MOI for P. vivax and P. falciparum were 2.16 and 2.68, respectively, which were significantly higher than that of microsatellite markers and short amplicon (117 bp) deep sequencing. Multiclonal infections were detected in 62.2% of the samples for P. vivax and 74.8% of the samples for P. falciparum. Four out of the five subjects with recurrent P. vivax malaria were found to be a relapse 44–65 days after clearance of parasites. No difference was observed in MOI among P. vivax patients of different symptoms, ages and genders. Similar patterns were also observed in P. falciparum except for one study site in Kenyan lowland areas with significantly higher MOI. Conclusions The study used a novel method to evaluate Plasmodium MOI and molecular epidemiological patterns by long amplicon ultra-deep sequencing. The complexity of infections were similar among age groups, symptoms, genders, transmission settings (spatial heterogeneity), as well as over years (pre- vs. post-scale-up interventions). This study demonstrated that long amplicon deep sequencing is a useful tool to investigate multiplicity and molecular epidemiology of Plasmodium parasite infections. Electronic supplementary material The online version of this article (10.1186/s12936-018-2337-y) contains supplementary material, which is available to authorized users.
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Affiliation(s)
- Daibin Zhong
- Program in Public Health, University of California at Irvine, Irvine, CA, 92617, USA.
| | - Eugenia Lo
- Department of Biological Sciences, University of North Carolina at Charlotte, Charlotte, NC, 28223, USA
| | - Xiaoming Wang
- Program in Public Health, University of California at Irvine, Irvine, CA, 92617, USA
| | - Delenasaw Yewhalaw
- Department of Medical Laboratory Sciences, Faculty of Health Sciences, Jimma University, Jimma, Ethiopia.,Tropical and Infectious Diseases Research Center, Jimma University, Jimma, Ethiopia
| | - Guofa Zhou
- Program in Public Health, University of California at Irvine, Irvine, CA, 92617, USA
| | - Harrysone E Atieli
- Centre for Global Health Research, Kenya Medical Research Institute, Kisumu, Kenya
| | - Andrew Githeko
- Centre for Global Health Research, Kenya Medical Research Institute, Kisumu, Kenya
| | | | - Ming-Chieh Lee
- Program in Public Health, University of California at Irvine, Irvine, CA, 92617, USA
| | - Yaw Afrane
- Department of Medical Microbiology, College of Health Sciences, University of Ghana, Accra, Ghana
| | - Guiyun Yan
- Program in Public Health, University of California at Irvine, Irvine, CA, 92617, USA.
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Koepfli C, Ome-Kaius M, Jally S, Malau E, Maripal S, Ginny J, Timinao L, Kattenberg JH, Obadia T, White M, Rarau P, Senn N, Barry AE, Kazura JW, Mueller I, Robinson LJ. Sustained Malaria Control Over an 8-Year Period in Papua New Guinea: The Challenge of Low-Density Asymptomatic Plasmodium Infections. J Infect Dis 2017; 216:1434-1443. [PMID: 29029179 PMCID: PMC5853328 DOI: 10.1093/infdis/jix507] [Citation(s) in RCA: 33] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/24/2017] [Accepted: 09/19/2017] [Indexed: 12/31/2022] Open
Abstract
Background The scale-up of effective malaria control in the last decade has resulted in a substantial decline in the incidence of clinical malaria in many countries. The effects on the proportions of asymptomatic and submicroscopic infections and on transmission potential are yet poorly understood. Methods In Papua New Guinea, vector control has been intensified since 2008, and improved diagnosis and treatment was introduced in 2012. Cross-sectional surveys were conducted in Madang Province in 2006 (with 1280 survey participants), 2010 (with 2117 participants), and 2014 (with 2516 participants). Infections were quantified by highly sensitive quantitative polymerase chain reaction (PCR) analysis, and gametocytes were quantified by reverse-transcription qPCR analysis. Results Plasmodium falciparum prevalence determined by qPCR decreased from 42% in 2006 to 9% in 2014. The P. vivax prevalence decreased from 42% in 2006 to 13% in 2010 but then increased to 20% in 2014. Parasite densities decreased 5-fold from 2006 to 2010; 72% of P. falciparum and 87% of P. vivax infections were submicroscopic in 2014. Gametocyte density and positivity correlated closely with parasitemia, and population gametocyte prevalence decreased 3-fold for P. falciparum and 29% for P. vivax from 2010 to 2014. Conclusions Sustained control has resulted in reduced malaria transmission potential, but an increasing proportion of gametocyte carriers are asymptomatic and submicroscopic and represent a challenge to malaria control.
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Affiliation(s)
- Cristian Koepfli
- Population Health and Immunity Division, Walter and Eliza Hall Institute, Melbourne, Australia
- Department of Medical Biology, University of Melbourne, Parkville, Australia
- University of California–Irvine
| | - Maria Ome-Kaius
- Population Health and Immunity Division, Walter and Eliza Hall Institute, Melbourne, Australia
- Department of Medical Biology, University of Melbourne, Parkville, Australia
- Papua New Guinea Institute of Medical Research, Madang
| | | | - Elisheba Malau
- Population Health and Immunity Division, Walter and Eliza Hall Institute, Melbourne, Australia
- Department of Medical Biology, University of Melbourne, Parkville, Australia
| | | | - Jason Ginny
- Papua New Guinea Institute of Medical Research, Madang
| | | | - Johanna Helena Kattenberg
- Population Health and Immunity Division, Walter and Eliza Hall Institute, Melbourne, Australia
- Papua New Guinea Institute of Medical Research, Madang
| | - Thomas Obadia
- Malaria: Parasites & Hosts Unit, Department of Parasites and Insect Vectors, Institut Pasteur, Paris, France
- Bioinformatics and Biostatistics Hub, Center for Bioinformatics, Biostatistics, and Integrative Biology, Institut Pasteur, Paris, France
| | - Michael White
- Population Health and Immunity Division, Walter and Eliza Hall Institute, Melbourne, Australia
- Medical Research Council Centre for Outbreak Analysis and Modelling, Department of Infectious Disease Epidemiology, Imperial College London, United Kingdom
| | - Patricia Rarau
- School of Population and Global Health, University of Melbourne, Parkville, Australia
- Papua New Guinea Institute of Medical Research, Madang
| | - Nicolas Senn
- Papua New Guinea Institute of Medical Research, Madang
- Swiss Tropical and Public Health Institute, Basel, Switzerland
| | - Alyssa E Barry
- Population Health and Immunity Division, Walter and Eliza Hall Institute, Melbourne, Australia
- Department of Medical Biology, University of Melbourne, Parkville, Australia
| | | | - Ivo Mueller
- Population Health and Immunity Division, Walter and Eliza Hall Institute, Melbourne, Australia
- Department of Medical Biology, University of Melbourne, Parkville, Australia
- Malaria: Parasites & Hosts Unit, Department of Parasites and Insect Vectors, Institut Pasteur, Paris, France
- Barcelona Center for International Health, Barcelona, Spain
| | - Leanne J Robinson
- Population Health and Immunity Division, Walter and Eliza Hall Institute, Melbourne, Australia
- Department of Medical Biology, University of Melbourne, Parkville, Australia
- Burnet Institute, Melbourne, Australia
- Papua New Guinea Institute of Medical Research, Madang
- Correspondence: L. Robinson, PhD, MPH, Walter and Eliza Hall Institute, 1G Royal Parade, Parkville VIC 3052, Australia ()
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Das R, Dhiman RC, Savargaonkar D, Anvikar AR, Valecha N. Genotyping of Plasmodium vivax by minisatellite marker and its application in differentiating relapse and new infection. Malar J 2016; 15:115. [PMID: 26912225 PMCID: PMC4766672 DOI: 10.1186/s12936-016-1139-3] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/18/2015] [Accepted: 02/02/2016] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND Plasmodium vivax malaria is a major public health problem in India. Control of vivax malaria is challenging due to various factors including relapse which increase the burden significantly. There is no well studied marker to differentiate relapse from reinfection. This creates hindrance in search for anti-relapse medicines. The genomic study of minisatellite can help in characterization of relapse and new infection of vivax malaria. METHODS Eighty-eight samples of P. vivax were collected from malaria clinic. All the 14 chromosomes of P. vivax were scanned for minisatellite marker by Tandem Repeat Finder software Version 4.07b. Minisatellite marker CH1T1M13779 from chromosome one was applied for genotyping in 88 samples of P. vivax including 2 recurrence cases. RESULTS Whole genome of P. vivax was scanned and found to have one hundred minisatellite markers. CH1T1M13779 minisatellite marker from chromosome-1 was used for amplification in 88 samples of P. vivax. Of 66 amplified samples, 14 alleles were found with varied allele frequency. The base size of 280 (13.63 %) 320 bp (13.63 %) and 300 bp (16.66 %) showed the predominant allele in the P. vivax population. Genotyping of two paired samples (day 0 and day relapse) could demonstrate the presence of relapse and reinfection. CONCLUSION The CH1T1M13779 can be potential minisatellite marker which can be used to differentiate between relapse and new infection of P. vivax strain.
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Affiliation(s)
- Ram Das
- National Institute of Malaria Research (ICMR), Sector-8, Dwarka, New Delhi, 110077, India.
| | - Ramesh C Dhiman
- National Institute of Malaria Research (ICMR), Sector-8, Dwarka, New Delhi, 110077, India.
| | - Deepali Savargaonkar
- National Institute of Malaria Research (ICMR), Sector-8, Dwarka, New Delhi, 110077, India.
| | - Anupkumar R Anvikar
- National Institute of Malaria Research (ICMR), Sector-8, Dwarka, New Delhi, 110077, India.
| | - Neena Valecha
- National Institute of Malaria Research (ICMR), Sector-8, Dwarka, New Delhi, 110077, India.
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Do mixed infections matter? Assessing virulence of mixed-clone infections in experimental human and murine malaria. INFECTION GENETICS AND EVOLUTION 2015; 36:82-91. [PMID: 26334940 DOI: 10.1016/j.meegid.2015.08.041] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/30/2015] [Revised: 08/27/2015] [Accepted: 08/27/2015] [Indexed: 01/26/2023]
Abstract
BACKGROUND Malaria parasites within an individual infection often consist of multiple strains (clonal populations) of a single species, which have the potential to interact both with one another, and with the host immune system. Several effects of these interactions have been measured in different parasite systems including competition and mutualism; however, direct observation of these effects in human malaria has been limited by sampling complexities and inherent ethical limitations. METHODS Using multiple complementary epidemiological models, we propose a suite of analyses to more fully utilize data from challenge experiments, and re-examine historical human challenge studies with mixed-strain Plasmodium vivax inocula. We then compare these results with murine model systems using mixed-strain Plasmodium yoelii or Plasmodium chabaudi, to explore the utility of these methods in fully utilizing these data, including the first quantitative estimates of effect sizes for mixed-strain parasitemia. These models also provide a method to assess consistency within these animal model systems. RESULTS We find that amongst a limited set of P. vivax (incubation time) and P. yoelii infections (time-to-mortality), survival times at a study population-level are intermediate between each single-clone infection, and are not dominated by the more virulent clone; in P. vivax relapses, mixed clone infections also show intermediate survival curves. In these infections, the results strongly suggest that highly virulent clones have their virulence attenuated by the presence of less-virulent clones. The analysis of multiple experiments with P. chabaudi suggests greater nuances in the interactions between strains, and that mortality and time-to-event in mixed-strain infections are both indistinguishable from single infections with the more virulent strain. CONCLUSIONS These divergent dynamics support earlier work that suggested drivers of virulence may differ in fundamental ways between malaria species that are reticulocyte-specific and those that readily infect all red blood cell stages which should be studied in greater detail. The effect sizes (magnitude of biological effects) from these analyses are significant, and suggest the potential for important gains in malaria control by greater incorporation of evolutionary epidemiology theory. Moreover, we suggest that using these epidemiological models may generally allow fuller use of data from experimentally challenging animal model experiments.
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7
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Manrique P, Hoshi M, Fasabi M, Nolasco O, Yori P, Calderón M, Gilman RH, Kosek MN, Vinetz JM, Gamboa D. Assessment of an automated capillary system for Plasmodium vivax microsatellite genotyping. Malar J 2015; 14:326. [PMID: 26293655 PMCID: PMC4546211 DOI: 10.1186/s12936-015-0842-9] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/24/2015] [Accepted: 08/08/2015] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND Several platforms have been used to generate the primary data for microsatellite analysis of malaria parasite genotypes. Each has relative advantages but share a limitation of being time- and cost-intensive. A commercially available automated capillary gel cartridge system was assessed in the microsatellite analysis of Plasmodium vivax diversity in the Peruvian Amazon. METHODS The reproducibility and accuracy of a commercially-available automated capillary system, QIAxcel, was assessed using a sequenced PCR product of 227 base pairs. This product was measured 42 times, then 27 P. vivax samples from Peruvian Amazon subjects were analyzed with this instrument using five informative microsatellites. Results from the QIAxcel system were compared with a Sanger-type sequencing machine, the ABI PRISM(®) 3100 Genetic Analyzer. RESULTS Significant differences were seen between the sequenced amplicons and the results from the QIAxcel instrument. Different runs, plates and cartridges yielded significantly different results. Additionally, allele size decreased with each run by 0.045, or 1 bp, every three plates. QIAxcel and ABI PRISM systems differed in giving different values than those obtained by ABI PRISM, and too many (i.e. inaccurate) alleles per locus were also seen with the automated instrument. CONCLUSIONS While P. vivax diversity could generally be estimated using an automated capillary gel cartridge system, the data demonstrate that this system is not sufficiently precise for reliably identifying parasite strains via microsatellite analysis. This conclusion reached after systematic analysis was due both to inadequate precision and poor reproducibility in measuring PCR product size.
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Affiliation(s)
- Paulo Manrique
- Malaria Laboratory, Institute of Tropical Medicine Alexander von Humboldt, Universidad Peruana Cayetano Heredia, Lima, Peru.
| | - Mari Hoshi
- Malaria Laboratory, Institute of Tropical Medicine Alexander von Humboldt, Universidad Peruana Cayetano Heredia, Lima, Peru.
| | | | - Oscar Nolasco
- Malaria Laboratory, Institute of Tropical Medicine Alexander von Humboldt, Universidad Peruana Cayetano Heredia, Lima, Peru.
| | - Pablo Yori
- Department of International Health, Johns Hopkins School of Public Health, Baltimore, MD, USA.
| | - Martiza Calderón
- Division of Infectious Diseases, Department of Medicine, University of California San Diego, La Jolla, CA, USA.
| | - Robert H Gilman
- Department of International Health, Johns Hopkins School of Public Health, Baltimore, MD, USA.
| | - Margaret N Kosek
- Department of International Health, Johns Hopkins School of Public Health, Baltimore, MD, USA.
| | - Joseph M Vinetz
- Malaria Laboratory, Institute of Tropical Medicine Alexander von Humboldt, Universidad Peruana Cayetano Heredia, Lima, Peru. .,Division of Infectious Diseases, Department of Medicine, University of California San Diego, La Jolla, CA, USA.
| | - Dionicia Gamboa
- Malaria Laboratory, Institute of Tropical Medicine Alexander von Humboldt, Universidad Peruana Cayetano Heredia, Lima, Peru. .,Departamento de Ciencias Celulares y Moleculares, Universidad Peruana Cayetano Heredia, Lima, Peru.
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Differing Patterns of Selection and Geospatial Genetic Diversity within Two Leading Plasmodium vivax Candidate Vaccine Antigens. PLoS Negl Trop Dis 2014; 8:e2796. [PMID: 24743266 PMCID: PMC3990511 DOI: 10.1371/journal.pntd.0002796] [Citation(s) in RCA: 37] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/12/2013] [Accepted: 03/05/2014] [Indexed: 02/04/2023] Open
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Development of a capillary electrophoresis-based heteroduplex tracking assay to measure in-host genetic diversity of initial and recurrent Plasmodium vivax infections in Cambodia. J Clin Microbiol 2013; 52:298-301. [PMID: 24131693 DOI: 10.1128/jcm.02274-13] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
A heteroduplex tracking assay used to genotype Plasmodium vivax merozoite surface protein 1 was adapted to a capillary electrophoresis format, obviating the need for radiolabeled probes and allowing its use in settings where malaria is endemic. This new assay achieved good allelic discrimination and detected high multiplicities of infection in 63 P. vivax infections in Cambodia. More than half of the recurrent parasitemias sampled displayed identical or highly related genotypes compared to the initial genotype, suggesting that they represented relapses.
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Activation of minority-variant Plasmodium vivax hypnozoites following artesunate + amodiaquine treatment in a 23-year old man with relapsing malaria in Antananarivo, Madagascar. Malar J 2013; 12:177. [PMID: 23721298 PMCID: PMC3671981 DOI: 10.1186/1475-2875-12-177] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/04/2013] [Accepted: 05/27/2013] [Indexed: 12/25/2022] Open
Abstract
In endemic areas, Plasmodium vivax relapses are difficult to distinguish from new infections. Genotyping of patients who experience relapse after returning to a malaria-free area can be used to explore the nature of hypnozoite activation and relapse. This paper describes a person who developed P. vivax malaria for the first time after travelling to Boriziny in the malaria endemic coastal area of Madagascar, then suffered two P. vivax relapses 11 weeks and 21 weeks later despite remaining in Antananarivo in the malaria-free central highlands area. He was treated with the combination artesunate + amodiaquine according to the national malaria policy in Madagascar. Genotyping by PCR-RFLP at pvmsp-3α as well as pvmsp1 heteroduplex tracking assay (HTA) showed the same dominant genotype at each relapse. Multiple recurring minority variants were also detected at each relapse, highlighting the propensity for multiple hypnozoite clones to activate simultaneously to cause relapse.
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Lin JT, Patel JC, Kharabora O, Sattabongkot J, Muth S, Ubalee R, Schuster AL, Rogers WO, Wongsrichanalai C, Juliano JJ. Plasmodium vivax isolates from Cambodia and Thailand show high genetic complexity and distinct patterns of P. vivax multidrug resistance gene 1 (pvmdr1) polymorphisms. Am J Trop Med Hyg 2013; 88:1116-23. [PMID: 23509126 DOI: 10.4269/ajtmh.12-0701] [Citation(s) in RCA: 35] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022] Open
Abstract
Plasmodium vivax accounts for an increasing fraction of malaria infections in Thailand and Cambodia. We compared P. vivax genetic complexity and antimalarial resistance patterns in the two countries. Use of a heteroduplex tracking assay targeting the merozoite surface protein 1 gene revealed that vivax infections in both countries are frequently polyclonal (84%), with parasites that are highly diverse (HE = 0.86) but closely related (GST = 0.18). Following a history of different drug policies in Thailand and Cambodia, distinct patterns of antimalarial resistance have emerged: most Cambodian isolates harbor the P. vivax multidrug resistance gene 1 (pvmdr1) 976F mutation associated with chloroquine resistance (89% versus 8%, P < 0.001), whereas Thai isolates more often display increased pvmdr1 copy number (39% versus 4%, P < 0.001). Finally, genotyping of paired isolates from individuals suspected of suffering relapse supports a complex scheme of relapse whereby recurrence of multiple identical variants is sometimes accompanied by the appearance of novel variants.
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Affiliation(s)
- Jessica T Lin
- Division of Infectious Diseases, University of North Carolina School of Medicine, Chapel Hill, NC 27599, USA.
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